doc/src/library/glossary.im - oransc/ric-plt/lib/rmr - Gitiles


 .if false
 ==================================================================================
 	Copyright (c) 2019 Nokia
 	Copyright (c) 2018-2019 AT&T Intellectual Property.

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
 ==================================================================================
 .fi


 .dv term ^&half_space ^&di($1)
 .ix pause

 &h1(Appendix  &gloss_appendix -- Glossary)

 Many terms in networking can be interpreted with multiple meanings,
 and several terms used in this document are RMR specific.  The
 following definitions are the meanings of terms used within this
 document and should help the reader to understand the intent of
 meaning.

 &beg_dlist( &1.0i Helvetica-bold )
 &term(application) A programme which uses RMR to send and/or receive
 		   messages to/from another RMR based application.

 &term(Critical error)	An error that RMR has encountered which will
 			prevent further successful processing by
 			RMR. Critical errors usually indicate that the
 			application should abort.

 &term(Endpoint) An RMR based application that is defined as being
 			capable of receiving one or more types of
 			messages (as defined by a &ital(message key.)
 			.sm )

 &term(Environment variable) A key/value pair which is set externally
 			to the application, but which is available to
 			the application (and referenced libraries)
 			through the &cw(getenv) system
 			call. Environment variables are the main
 			method of communicating information such as
 			port numbers to RMR.

 &term(Error) An abnormal condition that RMR has encountered, but will
 			not affect the overall processing by RMR, but
 			may impact certain aspects such as the ability
 			to communicate with a specific endpoint.
 			Errors generally indicate that something,
 			usually external to RMR, must be addressed.

 &term(Host name) The name of the host as returned by the
 			&cw(gethostbyname) system call. In a
 			containerised  environment this might be the
 			container or service name depending on how the
 			container is started. From RMR's point of
 			view, a host name can be used to resolve an
 			&ital(endpoint) definition in a &ital(route
 			table.)

 &term(IP)	Internet protocol. A low level transmission protocol
 			which governs the transmission of datagrams
 			across network boundaries.

 &term(Listen socket) A &ital(TCP) socket used to await incoming
 			connection requests. Listen sockets are
 			defined by an interface and port number
 			combination where the port number is unique
 			for the interface.

 &term(Message) A series of bytes transmitted from the application to
 			another RMR based application. A message is
 			comprised of RMR specific data (a header), and
 			application data (a payload).

 &term(Message buffer) A data structure used to describe a message
 			which is to be sent or has been received. The
 			message buffer includes the payload length,
 			message type, message source, and other
 			information.

 &term(Messgae type) A signed integer (0-32000) which identifies the
 			type of message being transmitted, and is one
 			of the two components of a &ital(routing key.)
 			See &ital(Subscription ID.)

 &term(Payload) The portion of a message which holds the user data to
 			be transmitted to the remote &ital(endpoint.)
 			The payload contents are completely
 			application defined.

 &term(RMR context) A set of information which defines the current
 			state of the underlying transport connections
 			that RMR is managing. The application will be
 			give a context reference (pointer) that is
 			supplied to most RMR functions as the first
 			parameter.

 &term(Round robin) The method of selecting an &ital(endpoint) from a
 			list such that all &ital(endpoints) are
 			selected before starting at the head of the list.

 &term(Route table) A series of "rules" which define the possible
 	    		&ital(endpoints) for each &ital(message key.)

 &term(Route table manager) An application responsible for building a
 			&ital(route table) and then distributing it to
 			all applicable RMR based applications.

 &term(Routing) The process of selecting an &ital(endpoint) which will
 be the recipient of a message.

 &term(Routing key) A combination of &ital(message type) and
 			&ital(subscription ID) which RMR uses to
 			select the destination &ital(endpoint) when
 			sending a message.

 &term(Source) The sender of a message.


 &term(Subscription ID) A signed integer value (0-32000) which
 			identifies the subscription characteristic of
 			a message. It is used in conjunction with the
 			&ital(message type) to determine the
 			&ital(routing key.)

 &term(Target) The &ital(endpoint) selected to receive a message.

 &term(TCP)	Transmission Control Protocol. A connection based
 			internet protocol which provides for lossless
 			packet transportation, usually over IP.

 &term(Thread)	Also called a &ital(process thread, or pthread.)  This
 			is a lightweight process which executes in
 			concurrently with the application and shares
 			the same address space. RMR uses threads to
 			manage asynchronous functions such as route
 			table updates.

 &Term(Trace information)  An optional portion of the message buffer
 			that the application may populate with data
 			that allows for tracing the progress of the
 			transaction or application activity across
 			components. RMR makes no use of this data.

 &term(Transaction ID) A fixed number of bytes in the &ital(message
 			buffer) which the application may populate
 			with information related to the
 			transaction. RMR makes use of the transaction
 			ID for matching response messages with the
 			&c(rmr_call) function is used to send a
 			message.

 &term(Transient failure) An error state that is believed to be short
 			lived and that the operation, if retried by
 			the  application, might be successful. C
 			programmers will recognise this as
 			&cw(EAGAIN.)

 &term(Warning) A warning occurs when RMR has encountered something
 			that it believes isn't correct, but has a
 			defined work round.

 &term(Wormhole) A direct connection managed by RMR between the user
 			application and a remote, RMR based, application.

 &end_dlist

 .ix resume

	.if false
	==================================================================================
	Copyright (c) 2019 Nokia
	Copyright (c) 2018-2019 AT&T Intellectual Property.

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	==================================================================================
	.fi


	.dv term ^&half_space ^&di($1)
	.ix pause

	&h1(Appendix &gloss_appendix -- Glossary)

	Many terms in networking can be interpreted with multiple meanings,
	and several terms used in this document are RMR specific. The
	following definitions are the meanings of terms used within this
	document and should help the reader to understand the intent of
	meaning.

	&beg_dlist( &1.0i Helvetica-bold )
	&term(application) A programme which uses RMR to send and/or receive
	messages to/from another RMR based application.

	&term(Critical error) An error that RMR has encountered which will
	prevent further successful processing by
	RMR. Critical errors usually indicate that the
	application should abort.

	&term(Endpoint) An RMR based application that is defined as being
	capable of receiving one or more types of
	messages (as defined by a &ital(message key.)
	.sm )

	&term(Environment variable) A key/value pair which is set externally
	to the application, but which is available to
	the application (and referenced libraries)
	through the &cw(getenv) system
	call. Environment variables are the main
	method of communicating information such as
	port numbers to RMR.

	&term(Error) An abnormal condition that RMR has encountered, but will
	not affect the overall processing by RMR, but
	may impact certain aspects such as the ability
	to communicate with a specific endpoint.
	Errors generally indicate that something,
	usually external to RMR, must be addressed.

	&term(Host name) The name of the host as returned by the
	&cw(gethostbyname) system call. In a
	containerised environment this might be the
	container or service name depending on how the
	container is started. From RMR's point of
	view, a host name can be used to resolve an
	&ital(endpoint) definition in a &ital(route
	table.)

	&term(IP) Internet protocol. A low level transmission protocol
	which governs the transmission of datagrams
	across network boundaries.

	&term(Listen socket) A &ital(TCP) socket used to await incoming
	connection requests. Listen sockets are
	defined by an interface and port number
	combination where the port number is unique
	for the interface.

	&term(Message) A series of bytes transmitted from the application to
	another RMR based application. A message is
	comprised of RMR specific data (a header), and
	application data (a payload).

	&term(Message buffer) A data structure used to describe a message
	which is to be sent or has been received. The
	message buffer includes the payload length,
	message type, message source, and other
	information.

	&term(Messgae type) A signed integer (0-32000) which identifies the
	type of message being transmitted, and is one
	of the two components of a &ital(routing key.)
	See &ital(Subscription ID.)

	&term(Payload) The portion of a message which holds the user data to
	be transmitted to the remote &ital(endpoint.)
	The payload contents are completely
	application defined.

	&term(RMR context) A set of information which defines the current
	state of the underlying transport connections
	that RMR is managing. The application will be
	give a context reference (pointer) that is
	supplied to most RMR functions as the first
	parameter.

	&term(Round robin) The method of selecting an &ital(endpoint) from a
	list such that all &ital(endpoints) are
	selected before starting at the head of the list.

	&term(Route table) A series of "rules" which define the possible
	&ital(endpoints) for each &ital(message key.)

	&term(Route table manager) An application responsible for building a
	&ital(route table) and then distributing it to
	all applicable RMR based applications.

	&term(Routing) The process of selecting an &ital(endpoint) which will
	be the recipient of a message.

	&term(Routing key) A combination of &ital(message type) and
	&ital(subscription ID) which RMR uses to
	select the destination &ital(endpoint) when
	sending a message.

	&term(Source) The sender of a message.


	&term(Subscription ID) A signed integer value (0-32000) which
	identifies the subscription characteristic of
	a message. It is used in conjunction with the
	&ital(message type) to determine the
	&ital(routing key.)

	&term(Target) The &ital(endpoint) selected to receive a message.

	&term(TCP) Transmission Control Protocol. A connection based
	internet protocol which provides for lossless
	packet transportation, usually over IP.

	&term(Thread) Also called a &ital(process thread, or pthread.) This
	is a lightweight process which executes in
	concurrently with the application and shares
	the same address space. RMR uses threads to
	manage asynchronous functions such as route
	table updates.

	&Term(Trace information) An optional portion of the message buffer
	that the application may populate with data
	that allows for tracing the progress of the
	transaction or application activity across
	components. RMR makes no use of this data.

	&term(Transaction ID) A fixed number of bytes in the &ital(message
	buffer) which the application may populate
	with information related to the
	transaction. RMR makes use of the transaction
	ID for matching response messages with the
	&c(rmr_call) function is used to send a
	message.

	&term(Transient failure) An error state that is believed to be short
	lived and that the operation, if retried by
	the application, might be successful. C
	programmers will recognise this as
	&cw(EAGAIN.)

	&term(Warning) A warning occurs when RMR has encountered something
	that it believes isn't correct, but has a
	defined work round.

	&term(Wormhole) A direct connection managed by RMR between the user
	application and a remote, RMR based, application.

	&end_dlist

	.ix resume